Sonar systems

ABSTRACT

A vessel-mountable integrated sonar system is provided. The vessel-mountable integrated sonar system comprises at least one imaging sonar data acquisition device and at least one processing system electronically and removably connected to the at least one imaging sonar data acquisition device, wherein the sonar data acquisition device preferably provides acoustic data to the processing system, producing sonar imageries utilizing the acoustic data, and wherein the system provides digital tilt and azimuth direction feedback for accurate geo-referencing of data to localize targets of interest.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/829,822, filed Jul. 27, 2007, which claims priority to U.S.Provisional Application No. 60/833,875 filed Jul. 27, 2006. Thesepriority patent applications are incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

The disclosed invention relates to vessel-mountable sonar systems, andparticularly vessel-mountable high resolution imaging sonar systemshaving homing and/or geo-referencing capabilities such that vesseloperators can deploy, navigate with, and utilize the sonar systems tolocate, identify, and investigate various targets in underwaterenvironments.

BACKGROUND OF THE INVENTION

Many vessel-mountable sonar systems are known in the art. Examples ofsuch systems include depth sounder(s), simple obstacle avoidancesonar(s), side scan sonar(s), mechanical scanning sonar(s), and manualpole mount(s). The display methods of these vessel-mountable sonarsystems do not adequately facilitate navigation with the sonarimageries, and these systems are difficult to understand and challengingto operate while the vessel is moving. In addition, thesevessel-mountable sonar systems do not have the capability to providehigh definition resolution imaging from a moving platform on the vessel.

U.S. Pat. No. 7,035,166 discloses a sonar system comprising at least onesonar emitter, an array of sonar sensors configured to receive an echofrom an outgoing signal generated by the sonar emitter and generate araw data signal; at least one roll, tilt, and yaw sensor, an input froma sensor determining the latitude and longitude position of the sonaremitter; and circuitry adapted to collect the raw signal data, processthe raw signal data to provide image data. The image is rotatedresponsively to the roll, tilt and yaw orientation of the sonar systemas determined by the respective sensors. The roll, tilt and yaw sensorand image processing allows successive display of multiple images fromsuccessive transmissions to be oriented with the same fixed frame ofreference in a direction relative to the earth.

U.S. Pat. No. 7,173,879 discloses a sonar system comprising a broad beamtransmitter, a phased array receiver, a processor which utilizes anon-Fourier based beamformer, and correlation based processingtechniques to extract valid targets from the beamformed data where thenumber of targets to search for is based on the values attained from anAdaptive Target Population Estimator processing technique. The values ofthe eigenvalues and the slope of successive eigenvalues are used todetermine the number of targets to be searched for by the beamformer.

U.S. Pat. No. 7,123,546 discloses a sonar system comprising at least 2transmitters with varying field of views, a receive system with a fieldof view which encompasses all the field of views generated by thetransmitters, a control system designed to switch electronics betweentransmitters, and processing parameters set to correspond to thetransmitters where the controller allows for the transmission andreception of a single ping before the next transmission, allowing eachtransmission to be differentiated in time.

SUMMARY OF THE INVENTION

Vessel-mountable high resolution imaging sonar systems having homing,localization, and/or geo-referencing capabilities are provided. Thedisclosed vessel-mountable systems are compact and can be detached andstowed for portability, convenience and security. The disclosed systemsprovide simple operator interface and allows an operator to quicklynavigate a vessel towards targets of interest. The disclosed systemsalso provide directional image display alignment to allow an operator toeasily maintain a sense of direction on a vessel.

The disclosed systems additionally provide digital tilt and/or azimuthdirection feedback for accurate localization and geo-referencing of datato localize targets and/or generate image mosaics. Accurate localizationand geo-referencing of targets and imagery enables multi-ping targettracking and multi-ping imagery overlay to produce improved imagingresolution via coherent or incoherent imagery and three-dimensional (3D)mosaic generation. The disclosed systems enable automated sonar aimingat target positions, in tilt and azimuth, using navigational tools suchas compass(es) and/or global positioning device(s) (GPS), so that targetpositions can be selected by an operator on a imaging display, such thatthe sonar continuously aims at the targets' geo-referenced positions.This allows maintenance of proper sonar alignment independent of vesselalignment and position. Furthermore, the disclosed vessel-mountablesystems provide sunlight readable touch screen display(s) for controland image display device(s), allowing an operator to maintainequilibrium on the vessel and minimizing motion sickness.

In one embodiment, the disclosed vessel-mountable sonar system comprisesat least one high resolution sonar data acquisition and imaging system,and at least one processing system having data storage and displaycapabilities. In many embodiments, the vessel-mountable system alsocomprises a controllable positioning device. In this embodiment, thepositioning device may comprise a pan and tilt mechanism, and the sonardata acquisition system may be removably connected to the positioningdevice by way of a clamping mechanism. The sonar data acquisition systemand the positioning device, or the pan and tilt sonar module, may beremovably connected to a pole, rod, shaft, post, or the like, forming amountable pan and tilt sonar module. The mountable pan and tilt sonarmodule, comprising the sonar system and the positioning device, iselectronically and preferably removably connectible to the processingsystem. The processing system may also be electronically connected to anintegrated or stand-alone navigation system or elements of a navigationsystem, such as a compass, depth sounder, GPS system or the like.

The methods and systems of the disclosed invention may be used with orincorporate many different types of sonar data acquisition and imagingsystems capable of producing various types of images. Many types ofsonar systems are known in the art and may be incorporated in systems ofthe disclosed invention. The sonar data acquisition and imaging systempreferably provides high definition two dimensional (2D) orthree-dimensional (3D) sonar imagery utilizing multiple beams. Frequencysteered sonar systems of the type described in co-pending U.S. PatentPublication 2005/0007882 A1, which is incorporated herein by referencein its entirety, are preferred for use in many methods and systems ofthe disclosed invention. The sonar system may, for example, comprise a2D or 3D forward-looking sonar system of the types described inco-pending U.S. Patent Publication 2005/0007882 A1, it may comprise a 2Dbathymetry sonar system that produces a relatively thin fan beam for 3Dside and down scanning applications for optimizing the field of view ofan object or surface of interest, or it may comprise many other 2D or 3Dsonar systems. In one embodiment, the sonar system comprises at leastone tilt and roll sensor. The at least one tilt and roll sensor iscapable of providing tilt feedback to the processing system.

The positioning device positions and orients the sonar data acquisitionsystem, and is preferably controllable by the processing system and/orthe operator for aiming the sonar data acquisition system in a directionof interest, while being able to provide orientation information, suchas tilt and roll information, homing and/or geo-referencing feedback tothe processing system. The positioning device may be a pan & tiltdevice, pan only device, tilt only device, multi-axis positioningdevice, tilt with vessel orientation for pan, or the like. Thepositioning system may provide pivoting of a sonar data acquisitionsystem through a single or multiple axes, and may providing scanningalong a line on a single or multiple axes, or may provide rotation ofthe sonar data acquisition system through various arcs. The positioningdevice, in one embodiment, may be a ball joint-type positioning device.

The processing system, having data storage and display capabilities,comprises at least one processing unit which controls the mountable panand tilt sonar module. The processing system also collects, stores,computes, processes, and provides sonar data and signals, sonar imagery,and navigational data and processes. In one embodiment, the processingsystem is a personal computer of the type that is well known in the artand designed to operate in a marine environment. In another embodiment,the processing system is a processor system integrated with themountable pan and tilt sonar module. The processing system comprises orinterfaces with at least one image display device and a plurality ofcontrol inputs.

The image display device presents the sonar imagery to the operator, maydisplay predetermined or selected target and positioning information toan operator and, in some embodiments, the image display device may havecommand input capabilities and may be a touch screen having inputcapabilities. In another embodiment, the image display device issunlight readable. The image display device may be installed on thevessel's ceiling, console, walls, or at an operator control station, andit may comprise a heads-up image display device system. In anotherembodiment, the image display device may comprise or interface with aportable display which can be worn on or held by the operator or mountedelsewhere on a vessel. In yet another embodiment, the image displaydevice may be installed within another larger image display devicesystem having additional image display device components.

The processing system preferably interfaces with and acquires input froma navigational system or navigational components that may beincorporated in the system of the disclosed invention or may be anindependent system or group of components that interface with theprocessing system. In many embodiments, for example, a compass and/or aglobal positioning device (GPS) interface with the processing system andprovide location coordinates for various vessel and target locations.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed invention will be described in greater detail in thefollowing detailed description, with reference to the accompanyingdrawings, wherein:

FIG. 1 illustrates an embodiment of the disclosed vessel-mountable sonarsystem and its interface with various other systems;

FIG. 2 illustrates an exploded perspective view of an embodiment of avessel-mountable sonar positioning pan and tilt module;

FIG. 3A illustrates a top view of the vessel mountable pan and tiltsonar module shown in FIG. 2;

FIG. 3B illustrates a front view of the mountable pan and tilt sonarmodule shown in FIG. 2;

FIG. 3C illustrates a side view of the mountable pan and tilt sonarmodule shown in FIG. 2;

FIG. 3D illustrates a perspective view of the mountable pan and tiltsonar module shown in FIG. 2;

FIG. 4A illustrates a relationship between a sonar image orientation andthe sonar device and positioning module in an intuitive target displayprovided on an image display device; and

FIG. 4B illustrates another relationship between a sonar imageorientation and the sonar device and positioning module in anotherintuitive target display provided on an image display device.

DETAILED DESCRIPTION OF THE INVENTION

Vessel-mountable high resolution imaging sonar systems having homing,localization, and/or geo-referencing capabilities are provided. Thedisclosed vessel-mountable systems are preferably compact and can bedetached and stowed for portability, convenience, and security. Thedisclosed systems provide simple operator interface, and allow anoperator to quickly identify and navigate a vessel towards targets ofinterest. The disclosed systems also permit an operator to track aselected target or targets of interest on sonar imagery, and may providedirectional image display alignment, whereby the sonar image isdisplayed at an angle with respect to the vessel that corresponds to theorientation of the sonar acquisition and positioning device. Thisprovides a more intuitive interface for an operator and allows anoperator to easily track and steer toward an underwater target whilemaintaining a sense of direction on a vessel.

The disclosed systems additionally provide digital tilt and/or azimuthdirection feedback from the sonar data acquisition system andincorporate or interface with navigational tools for accurategeo-referencing of selected targets within the range of the sonarsystem, which permits accurate geo-referencing of selected targets.Accurate geo-referencing of targets allows the system to generate imagemosaics and to track targets and/or spatial coordinates, or to runpredetermined or selected underwater surveillance programs. Accurategeo-referencing of targets and imagery also enables multi-ping targettracking and multi-ping imagery overlay to produce improved imagingresolution via coherent or incoherent imagery and 3D mosaic generation.

The disclosed systems also enable automated sonar aiming at targetpositions, in tilt and azimuth, using navigational tools such ascompass(es) and/or global positioning device(s) (GPS), so that targetpositions may be selected by an operator by target coordinates or bypointing to a spatial location on a imaging display. Once one or moreunderwater targets are identified and geo-referenced, the sonar systemmay be instructed to continuously track, or aim at, the targets'geo-referenced positions. This provides maintenance of proper sonardirectional alignment and maintains the sonar imagery on one or moretarget locations independent of vessel alignment and position.Furthermore, the disclosed vessel-mountable systems may provide sunlightreadable touch screen display(s) for control and image displaydevice(s).

FIG. 1 shows one embodiment of a vessel-mountable integrated sonarsystem 10. The vessel-mountable sonar system 10 comprises at least onehigh resolution imaging sonar data acquisition device 20, at least onecomputer-controllable positioning device 30, at least one computersystem 40, and data storage 50 and display 60 components. The systemalso preferably incorporates or interfaces with at least onenavigational system 70 or one or more navigational components or tools.The terms processing system and computer system are used interchangeablyin this specification and no distinctions between the terms areintended. The processing or computer systems are preferably digital andhave data processing capabilities. Data storage may be incorporated inthe computer system and/or provided in an auxiliary data storage deviceor system. The display may likewise be incorporated in the computersystem or it may be provided as a separate display device thatinterfaces with the computer system.

As shown in FIG. 2, the sonar data acquisition device 20 is removablyconnected to the positioning device 30 by way of a clamping mechanism orthe like to form a pan and tilt sonar module 90. In one embodiment, thesonar data acquisition system 20 is removably connected to thepositioning device 30 by way of a plurality of brackets 80 and 120.Bracket 120 secures and fastens sonar data acquisition device 20 tobracket 80 by way of screws 130, although other types of fasteners maybe employed. Collectively, bracket 120, sonar data acquisition device20, and bracket 80 are secured and fastened to positioning device 30 byway of screws 140 and rotator arm 150. Rotator arm 150 is rotatablyconnected to bracket 80 and positioning device 30 by way of screws 160,allowing positioning device 30 to freely rotate. A pan and tilt mount170 is also connected to positioning device 30, allowing the positioningdevice 30 to freely pan and tilt.

FIG. 2 shows the pan and tilt sonar module 90 being removably connectedto a pole 100 by way of a plate mount 180, and screws 190 and 200,forming a mountable pan and tilt sonar module 110, although a rod, ashaft, a post, or the like maybe employed. In one embodiment, themountable pan and tilt sonar module 110 is removably installed to avessel via a quick release mounting mechanism 210 located in proximityto a distal end of pole 100. The mountable pan and tilt sonar module 110may be permanently bolted, for example, to the swim step on the aftsection of a vessel. The clamping mechanism 210 holds the pole 100firmly under the water when fully deployed. In one retracted position,the mountable pan and tilt sonar module 110 can also be loosened toallow pole 100 to be raised out of the water. In another retractingposition, the clamping mechanism 210 can also be rotated over the top ofthe mountable pan and tilt sonar module 110 to lay the raised pole 100across the swim steps of the vessel. These two retracted positions allowthe vessel to travel quickly without the need to completely remove andstow the mountable pan and tilt sonar module 110. When needed, pole 100can be completely removed from the pan and tilt sonar module 90 and bestowed in a safe location. In one embodiment, mountable pan and tiltsonar module 110 is installed to the inside wall of the vessel's cuddycabin by way of at least one mounting bracket. In another embodiment,mountable pan and tilt sonar module 110 is fixed mounted on the hull orthe transom of the vessel.

The mountable pan and tilt sonar module 110, comprising the sonar dataacquisition device 20 and the positioning device 30, is electronicallyand removably connected to the computer system 40. In one embodiment,the sonar data acquisition device 20 of the mountable pan and tilt sonarmodule 110 comprises at least one port from which the mountable pan andtilt sonar module 110 is connected to the computer system via, forexample, an Ethernet connection. In another embodiment, the positioningdevice 30 is electronically and wirelessly connected to the computersystem 40. Any radio frequency protocol or standard wireless internetprotocol known in the art may be employed. The computer system 40 isalso electronically connected to a navigation system 70. Target anglefeedback is provided from internal position sensors positioned in thepositioning device 30 and feedback is digitally sent to the computersystem 40.

The sonar data acquisition device 20 preferably utilizes multiple beamsto provide acoustic data to the computer system 40, which produces highdefinition two dimensional (2D) or three-dimensional (3D) sonar imageryutilizing the acoustic data. The sonar imagery may be produced, forexample, by multi-beam 2D imaging, multi-beam 3D imaging, mechanicalscanning 2D imaging sonar systems, 2D bathymetry, and the like. Thesonar data acquisition device 20 preferably comprises at least one tiltand roll sensor (not shown in the figures), which is capable ofproviding tilt feedback to the computer system 40. In one embodiment,the sonar data acquisition device 20 may be any of the frequency-steeredacoustic array systems as disclosed in U.S. Patent Publication No.2005/0007882 A1, which is incorporated herein by reference in itsentirety. In one example, the sonar data acquisition device 20 comprisesan acoustic array incorporating a plurality of acoustic transducerelements having aperiodic spacing and/or phasing, and the sonar dataacquisition device is capable of transmitting and/or receivingfrequency-steered acoustic beams having a field of view adjustable bymeans of frequency band selection. In another example, the sonar dataacquisition device 20 comprises an acoustic array capable oftransmitting and/or receiving frequency-steered acoustic beams in atleast two fields of view oriented in different directions, the arraycomprising a plurality of acoustic transducer elements, each of theelements being phase shifted with respect to neighboring elements, andeach of the elements being in electrical communication with a controllercapable of switching the polarity, the phase shifts, or interconnectionsof at least a portion of the elements to select an activefrequency-steered field of view.

In yet another example, the sonar data acquisition device 20 comprisesan acoustic array combination having a plurality of spaced acoustictransducer elements capable of transmitting and/or receivingfrequency-steered acoustic beams having a field of view adjustable bymeans of frequency band selection arranged at an angle to and insubstantially the same plane with at least one additional acousticarray, whereby the array combination is capable of transmitting and/orreceiving acoustic pulses in different fields of view in a single plane.In still another example, the sonar data acquisition device 20 comprisesan acoustic array combination having a plurality of spaced acoustictransducer elements capable of transmitting and/or receivingfrequency-steered acoustic beams having a field of view adjustable bymeans of frequency band selection arranged at an angle to and insubstantially the same plane with at least one additional acousticarray, arranged at an angle to and in a generally orthogonal plane tothe plane of at least one additional acoustic array, whereby the arraycombination is capable of transmitting and/or receiving acoustic pulsesin different fields of view in two planes that are generally orthogonalto one another.

The positioning device 30 is capable of positioning and orienting thesonar data acquisition device 20, and is capable of aiming the sonardata acquisition device 20 towards a direction of interest, while beingable to provide positioning and orientation feedback to the computersystem 40. The positioning device 30 may be a pan & tilt device, panonly device, tilt only device, multi-axis positioning device, tilt withvessel orientation for pan, or the like. In one embodiment, thedisclosed vessel-mountable sonar system 10 can utilize a tilt-onlyimplementation to carry out panning function by changing the heading ofthe vessel. Alternatively, the disclosed system 10 can also use a fixedmount imaging sonar data acquisition device 20 with no pan and tilt aslong as the vertical field of view is adequate to ensonify the bottom orwater column in a wide variety of depth environments.

The computer system 40 comprises at least one processing unit whichcontrols the mountable pan and tilt sonar module 110, and computersystem 40 also collects, stores, computes, processes, and provides sonardata and signals, sonar imagery, and navigational data and processes.The computer system 40 interfaces with at least one data storage system50 and/or at least one image display 60. The computer system 40preferably provides a user interface, such as a keyboard, an interactiveimage display device 60 such as a touchscreen, or another userinterface. An operator is preferably able to control the direction ofthe sonar by operating the positioning device 30 from the interface;select imaging modes and sonar images from the image display device 60from the interface; select targets and using the interface, andotherwise operate the sonar system 10 to locate, identify, display,inspect and track sonar targets. In one embodiment, a joystickcontroller is provided as an interface, wherein the joystick controlleris able to control both the sonar data acquisition device 20 and thepositioning device 30.

The computer system 40 may be integrated with the mountable pan and tiltsonar module 110, but is preferably a separate unit that communicateswith the sonar data acquisition device 20 and the positioning device 30.Communication between the computer system 40, the positioning device 30and/or the sonar data acquisition device 20 is preferably two-waycommunication, so that an operator may input instructions through theuser interface of the computer that controls the positioning device 30and the data collected by the sonar data acquisition device 20. Thecomputer system 40 comprises or is interfaceable with at least one imagedisplay device 60 and a plurality of control inputs. The image displaydevice 60 presents the imagery to the operator, and in one embodiment,the image display device 60 has input capabilities and may comprise atouch screen having input capabilities. In another embodiment, the imagedisplay device 60 may comprise a sunlight readable screen. The imagedisplay device 60 may be installed on the vessel's ceiling, console,walls, or on another part of the vessel, and it may be a heads-up imagedisplay device system that displays data and/or images on an accessoryscreen or device. In another embodiment, the image display device 60, oran accessory image display device 60 may comprise a portable displaywhich can be worn on or held by the operator. In yet another embodiment,the image display device 60 is installed within another larger imagedisplay device system.

The data storage system 50 connects to or forms a part of the computersystem 40 to save the collected acoustic data, sonar imagery, targetdata and imagery, sonar device orientation data, and navigational data,for example. This data may also be electronically transmitted, andoptionally wirelessly transmitted to a remote location for display,processing, or longer term or additional storage by way of any wired orwireless transmission systems and protocols that are known in the art.

The processing or computer system 40 of the disclosed inventionpreferably comprises or interfaces with one or more navigational tools,such as a compass and/or a global positioning device (GPS) forming partof a vessel navigational system 70. Any compasses and global positioningdevices known in the art may be incorporated in navigational system 70and interfaced with the processing or computer system 40 of thedisclosed invention using hard-wired and/or wireless protocols. Thenavigational system 70 may also incorporate navigational data such asthree dimensional charts including detailed latitude, longitude, depth,and navigational hazard and aid information, weather information, andthe like, or such information may be separately incorporated in orinterfaced with the processing or computer system 40 forming a part ofthe sonar system of the disclosed invention. The navigational system 70or components preferably provides spatial coordinates relating to theposition of the vessel and, interfaced with the sonar and processingsystems, may also provide spatial coordinates for various sonar targets.When interfaced with navigational data, the navigational system 70 mayalso provide spatial coordinates relating to the position of variousnavigational obstacles, aids, and the like.

An operator may use the computer system 40 and data storage system 50 tostore raw or processed data, such as acoustic sonar data, positioningdevice data, navigational data, or the like, for later retrieval andreview, or various programmed storage protocols may be provided andselectable by an operator. For example, navigational data can becollected and combined with the sonar data acquisition device 20positioning information provided by the pan and tilt sonar module 90 tounambiguously map spatial locations (i.e. pixels) shown on a sonar imageto a specific geo-referenced position, which is critical for accuratelymeasuring distances and creating geo-referenced mosaics and overlays ofthe collected data.

In operation, an operator preferably controls the mountable pan and tiltsonar module 110 from a user interface provided as part of the computersystem 40 and/or displayed on the image display device 60. The operatormay thus “point” the sonar data acquisition device 20 to variousunderwater areas or target(s) as desired. Alternatively, variousautomated inspection or surveillance routines may be selectable by theoperator and, when selected, perform a predetermined or selectable sonarinspection routine covering predetermined underwater areas with relationto the vessel. Real-time data relating to the orientation of thepositioning device 30 and the sonar module orientation is preferablycommunicated to the computer system 40 and displayable to the user onthe image display device 60. For example, relative pitch and yawinformation for what the sonar data acquisition device 20 and thepositioning device 30 is known and may be displayed. Additionally,because the sonar data acquisition module 90 is fixed with respect tothe vessel and the orientation of the module 90 is known, the pitch andyaw orientation of the vessel may be calculated and displayed to theoperator.

In preferred embodiments, in which the sonar data acquisition device 20and/or the positioning device 30 incorporates one or more tilt and rollsensor(s), and the absolute position is referenced and interfaced withthe sonar system 10, the target(s) shown on the image display device 60may have a true latitude and longitude associated with them. Targets maythus be accurately geo-referenced using the sonar system 10 of thedisclosed invention and, once a target is selected for tracking, thecomputer system 40 may automatically maintain the pan and tilt sonarmodule 90 aimed and pointed at the target independent of the vessel'sposition and orientation. Even if the target moves out of range, the panand tilt sonar module 90 can be aimed and pointed at the target toindicate to an operator where he needs to maneuver the vessel to locatethe target, and desired headings to the target may be provided anddisplayed to the operator. Once a target is identified on the imagedisplay device 60 and/or selected by an operator, and its positiongeo-referenced, the system may also maintain the selected target in thesonar system field of view and in the image display device 60 to theuser, and provide automated tracking of the selected target byautomatically positioning the sonar data acquisition device 20 in anappropriate orientation to maintain the selected target in anappropriate field of view. In this fashion, the sonar system of thedisclosed invention may provide continuous target maintenance andtracking.

Furthermore, an operator can detect a target in situ and mark the targeton the sonar image display device 60. Since a target of interest and thevessel are geo-referenced via the disclosed vessel-mountable system 10in a, for example, local self-consistent coordinate system, the sonardata acquisition device 20 can be constantly pointed to and aimed at thetarget and some indication by way of, for example, screen icon(s), ofthe expected screen location of the last known position of the targetcan be displayed. Thus, the disclosed system 10 has the advantage ofconstant monitoring of and rapid reacquisition of a target of interesteven if the operator loses contact with the target due to operatorattention lapses, targets moving out of the sonar system's range orfield of view, or occlusion of the target by acoustic obstacles, such asprop wash.

The absolute position and angle data of the sonar acquisition device mayalso be utilized to overlay on a chart and provide a large area mosaicdisplayable on the image display device 60, providing targetgeo-referencing information such as target latitude, longitude, anddepth information. The sonar data acquired from the disclosed system,over multiple pings, can be laid down on the chart as described above asa larger area mosaic image, with geo-referenced and accurate spatialpositioning and special dimensions. Each mosaic image may be assigned aunique identifier and the operator may have the ability to selectivelyturn “on and off” an individual mosaic image, or select from amongmultiple mosaic images. Larger mosaic images may be compiled and createdat the option of the operator and by manipulation of multiple mosaicimages.

Steering of the vessel underway can be utilized to home in on targets ofinterests. In this mode of operation, the operator can adjust the sonarmodule orientation to rapidly approach a target of interest. Since theimagery is within sight of the vessel's operator, he can use the imageryof a target to adjust the vessel's heading until the vessel is directedtowards the target. As the vessel moves closer to the target ofinterest, the pan and tilt sonar module 90 can easily be re-positionedand adjusted (e.g. reduce max range settings) to maintain a desireddisplay imagery. Homing in on a selected target visualized using thesonar system may also be accomplished in an automated fashion when thevessel's navigational and/or steering systems are interfaced with thesystem.

In one preferred embodiment, the sonar imagery on the image displaydevice 60 is preferably oriented to match the rotational angle of thesonar data acquisition device 20 and the pan and tilt sonar module 90,as shown in FIGS. 4A and 4B. When the pan and tilt sonar module 90 ispointed in the orientation shown in FIG. 4A, or directly “at” thetarget, for example, the sonar image provided on the display 60 has thesame orientation with respect to the target and the target(s) flows fromtop to bottom on the image display device 60. When the pan and tiltsonar module 90 is rotated so that it points at an angle with respect toor to the side of the vessel's center line 250, as shown in theorientation of FIG. 4B, the sonar image is also rotated on the imagedisplay device 60—at the same angle with respect to the centerline 250of the vessel. This feature allows the viewer to view the target(s) asit's oriented with respect to the viewer's and vessel's orientation andprovides an intuitive display feature, dramatically improving theoperator's ability to understand and dynamically react to the imagedisplay device 60 information, and consequently allowing ease innavigating the vessel based on the imagery.

The disclosed sonar system 10 can also be used to avoid navigationalhazards. In one embodiment, for example, the sonar system may beprogrammed to provide an indication, such as trigger an alarm, when atarget having a particular size or shape or another property isdetermined to be within range of the system, or within a particulardistance from the system and the vessel. This alerts an operator toinspect the sonar image, and the operator may investigate the target toidentify its position, character, and the like.

In another embodiment, the sonar system is interfaced with navigationalsystems such as (digital) charts that locate and identify navigationalhazards and may optionally also be interfaced with an automated vesselsteering system. In one embodiment, for example, the position ofnavigational hazard(s) indicated on a chart or another navigational aidare geo-referenced and input to the computer system controlling thesonar data acquisition device and image display device. As the vesseland sonar acquisition systems near an identified and geo-referencednavigational hazard, the system may provide a notification, such astrigger an alarm, to indicate that the navigational hazard is withinrange of the sonar system and the vessel. Various alarm ranges may beprogrammed or programmable in the computer system. In an integratedsystem, the vessel's steering system may be interfaced with the sonarsystem and may steer the vessel away from identified navigationalhazards or may maintain a predetermined or programmed or programmabledistance between the vessel and the identified navigational hazards oncethey're within range of the sonar data acquisition device. The sonarsystem may similarly be programmed to provide automated identificationand alarm

The sonar acquisition device may be provided in a generallyforward-looking and/or downward-looking orientation. If there arelimitations to adjusting the orientation of the sonar acquisition deviceusing a pan and tilt or similar mechanism, the field of view of the panand tilt sonar module 90 may be rotated, as required, to provide thedesired field of view. The sonar acquisition device may be positioned ina generally downward looking position, for example, and rotated by 90degrees around the center axis of the sonar system's housing tore-orient the sonar data acquisition device in a forward-lookingorientation. This may be achieved by loosening bracket 120 that holdsthe sonar data acquisition device 20 to the positioning device 30 andphysically rotating the sonar data acquisition device 20 by 90 degrees.

In addition, during operation, the sonar data acquisition system 20 mayact as a directional indicator via rotated imagery on the imagerydisplay 60 (FIGS. 4A and 4B), wherein the sonar data acquisition device20 is always pointed and aimed towards the closest point of approach toan identified or selected target displayed on the sonar image. In oneembodiment, when the latitude and longitude data of an identified targetof interest is known and the vessel is approaching the target ofinterest, the pan and tilt sonar module 90 is automatically oriented topoint and aim towards the target to provide steerage guidance for thevessel operator to steer the vessel toward the target, while minimizingthe operator's maneuvering task. In one embodiment, the disclosedvessel-mountable sonar system may incorporate a notification or alarmfeature, that is activated when the target is close to the position ofthe vessel or if the vessel begins to veer off the course towards thetarget. In another embodiment, multiple waypoints can be utilized tofully investigate an entire area of interest.

As mentioned above, navigational and real-time location data may beinput into or interfaced with the computer system 40, providing sonarimages that are mapped to a geo-referenced position. The geo-referencedposition and navigational data can be utilized to allow the user topoint and click on a target of interested and acquire the actualposition and/or depth of the target. Alternatively, a target of interestcan be chosen on the sonar imagery and the navigation system 70 aims andlocks into the target, allowing the vessel to be steered towards thetarget. The navigation system 70 may also track a moving targetautomatically by way of the geo-referenced position and navigationaldata.

In another embodiment, the navigational data, object geo-referencingroutine data, and the position of a moving target such as a diver, isintegrated in the computer system and may be displayed on the imagedisplay device 60. Using automated tracking routines, the computersystem 40 can automatically track the moving target and acquirecontinuous position and vector data of the target. For example, in oneembodiment, the operator can touch soft-keys on the image display device60 to operate the positioning device 30. This allows the operator tomanually aim the sonar data acquisition device 20 at targets ofinterest. In this embodiment, the vessel can be in a stationary positionand nearby underwater activities can still be monitored by the disclosedsystem 10. For example, the vessel can be tied to a dock and the pan andtilt sonar module 90 can be oriented toward a target on interest for adive operation. The divers can then enter the water and the operator canwatch the divers approach the target(s) while re-positioning the pan andtilt sonar module 90 to provide the best imagery or coverage or tracktarget(s) outside of the field of view. The operator can also sweep thepan and tilt sonar module 90 back and forth between multiple sceneswithin the system's imaging range. Further, the operator can direct thediver via acoustic communications or other techniques while monitoringthe diver's progress toward the a target by way of the disclosedvessel-mountable system 10.

It will be understood that the foregoing descriptions of variousembodiments of methods and systems of the disclosed invention are merelyillustrative of the invention and its varied embodiments. Modificationsto various aspects of the methods and systems of the disclosed inventionwill be apparent to those skilled in the art and are intended to fallwithin the scope and purview of this disclosure and the followingclaims.

1. A sonar system, comprising: (a) at least one sonar data acquisitiondevice; (b) at least one user interface allowing an operator to select adesired target for tracking; and (c) at least one processing systemelectronically and removably connected to the at least one sonar dataacquisition device and the at least one user interface; wherein thesonar data acquisition device provides acoustic data and orientationand/or positioning feedback based on the position of the sonaracquisition device to the processing system, and the processing systemacquires the desired target for tracking from the user interface andmaintains the at least one imaging sonar data acquisition device aimedand pointed at the desired target independent of the position andorientation of the vessel on which the sonar system is mountable.
 2. Thesonar system of claim 1, wherein the processing system incorporatesautomated tracking routines that automatically track the desired targetand acquire continuous position and vector data relating to the desiredtarget.
 3. The sonar system of claim 1, wherein the processing systemincorporates automated tracking routines that automatically track adesired moving target and acquire continuous position and vector datarelating to the desired moving target.
 4. The sonar system of claim 1,wherein the at least one sonar data acquisition device incorporates atleast one tilt and roll sensor that, during operation, references theabsolute position of the sonar data acquisition device.
 5. The sonarsystem of claim 1, wherein the processing system associates a desiredtarget for tracking with a latitude and longitude.
 6. The sonar systemof claim 1, wherein a navigational system is additionally interfacedwith the vessel mountable sonar system.
 7. The sonar system of claim 1,wherein a steering system is additionally interfaced with the vesselmountable sonar system.
 8. The sonar system of claim 1, wherein digitalcharts identifying navigational hazards are additionally interfaced withthe vessel mountable sonar system.
 9. A sonar system, comprising: (a) atleast one sonar data acquisition device; and (b) at least one processingsystem electronically and removably connected to the at least one sonardata acquisition device; wherein the sonar data acquisition deviceprovides acoustic data and orientation and/or positioning feedback basedon the position of the sonar acquisition device to the at least oneprocessing system, and the at least one processing system is capable ofperforming a predetermined or selectable sonar inspection routinecovering predetermined target areas with relation to the vessel on whichthe sonar system is mountable.
 10. The sonar system of claim 9, whereinthe at least one processing system is programmed with a plurality ofautomated surveillance routines selectable by the operator.
 11. A methodof providing continuous underwater target maintenance and tracking usinga sonar system incorporating a mountable pan and tilt sonar module, auser interface allowing an operator to select a desired underwatertarget, and a computer system for communicating with the sonar moduleand user interface and for processing acquired data, comprising:referencing and interfacing the absolute position of a sonar dataacquisition device; selecting an underwater target; geo-referencing theselected underwater target; acquiring real-time data relating to theorientation of the sonar data acquisition device; and automaticallymaintaining the sonar module aimed at the target independent of thevessel's position and orientation.
 12. A sonar system, comprising: (a)at least one imaging sonar data acquisition device utilizing multiplebeams; (b) at least one processing system electronically and removableconnected to the at least one imaging sonar data acquisition device and,based on sonar data acquired, providing high definition two dimensional(2D) or three-dimensional (3D) sonar imagery; and (c) a displayinterfacing with the at least one processing system for displaying sonarimagery; wherein the sonar acquisition device provides acoustic data andorientation and/or positioning feedback based on the position of thesonar acquisition device to the processing system and the processingsystem provides accurate geo-referencing of selected targets and 2D or3D sonar imagery.
 13. The sonar system of claim 12, wherein the sonarimagery is produced using multi-beam 2D imaging.
 14. The sonar system ofclaim 12, wherein the sonar imagery is produced using multi-beam 3Dimaging.
 15. The sonar system of claim 12, wherein the sonar imagery isproduced using mechanical scanning 2D imaging sonar systems.
 16. Thesonar system of claim 12, wherein the sonar imagery is produced using 2Dbathymetry.
 17. The sonar system of claim 12, wherein the sonar systemadditional incorporates multi-ping target tracking.
 18. The sonar systemof claim 12, wherein the sonar imagery is produced using multi-pingimagery overlay.